1. Field of the Invention
This invention generally relates to supporting structures for cushioning objects against mechanical shock during shipment and handling. A supporting arrangement is provided that is particularly advantageous for supporting irregular sheet-like shapes such as motor vehicle windshields in a standing or laid-flat orientation. A set of V-shaped supporting structures fit into the peripheral areas of a carton and preferably engage the top, bottom and lateral edges of a windshield or other irregular form. The windshield form may be trapezoidal, in which event the lateral V-shapes are tapered to engage the form snugly, and can be fixed to a carton wall to maintain a predetermined position relative to the form.
2. Prior Art
A variety of packaging products are known for cushioning articles during shipment, handling, storage and other situations in which there is a possibility of damage. The articles typically are protected in the first instance by an external box or carton. Damage to the shipped articles might occur in various ways. Short of damaging the contents, failure of the packaging can occur, presaging potential later damage to the articles because of loss of the protective function for which the container was designed.
Some typical types of damage to articles and/or their containers might result from fallover, inadvertent dropping over a vertical distance, lateral crushing, vertical crushing due to excessive weight loading in a stack, breach of a container by mechanical contact, rupture of seams or closures, loss of container integrity by wetting (especially for paperboard and corrugated craft), etc. Depending on the nature of the article, simple shock can damage the article even while the container envelope remains wholly intact.
It is naturally desirable to protect articles. However it is also appropriate to avoid unnecessarily heavy containers because of the associated expense. The expense of an unduly protective container structure is not limited to the cost of the container, but also may contribute to the shipping expense due to the weight or tare associated with the container and the additional volume of the container beyond the minimum size dictated by the article. Thus there are conflicting design choices to be made, with the optimal container being only just heavy and large enough to do the protective job needed in situations that are likely to be encountered by the container, with due regard to the probability of avoiding potential loss and the value of the article, if the container contents are indeed damaged.
A demanding sort of article for protection during shipping and handling is a glass sheet. Glass needs to be protected from impact. Glass is potentially sharp-edged and breakable. It is advantageously handled in an enclosure rather than directly. As a specific type of formed glass sheet, a windshield is likely to be stronger than a float glass pane of the same size, but on the other hand, is likely to be much heavier may be irregularly shaped, leading to added packaging demands.
U.S. Pat. No. D418,057xe2x80x94Morell discloses a die cut corrugated craft sheet that can enclose around a single windshield for protecting it in shipping. This sort of cover protects the windshield against damage from contact with smaller items, scratches and the like, but not against shock, for example from dropping the entire package from a truck or the like. Such a cover is useful, but does not contribute much in the way of independent support, as does an enclosing carton or box to carry the windshield. The cover functions are substantially limited to surface protection, i.e., wrapping.
One conventional way to protect an article is to provide a durable outer box or carton, and to insert a cushioning material between the article and the internal walls of the box or carton. The idea is to permit the cushioning material to yield resiliently and thus to damp the shock applied to the protected item when a shock is applied externally to the carton. The protected article becomes displaced within the carton. Such cushioning material can be rated for the compressive forces expected and for the weight and fragility of the product being protected. The resilience, damping character and thickness are chosen to provide optimal cushioning.
Cushioning material comes in many forms, and there are tradeoffs associated with the choice of material and how it is arranged. For example, highly resilient material may be a poor choice to protect frangible articles that are brittle or that are subject to resonance. Cushioning materials that are good for damping shocks may have a poor shape memory and become permanently deformed when compressed. Such materials are not effective if repeated shocks occur. If a cushioning material must be very thick, the size of the package becomes large.
An alternative approach that is possibly inconsistent with cushioning is to provide a heavy duty box or container and to support the article very durably therein. Packaging of this type is sometimes used for shipping a number of windshields in a stack, e.g., to an auto assembly plant. A heavy base and enclosing box holds a fixture that has receptacles for a number of windshields that are stacked and individually supported by the fixture. A heavy shipping fixture as described may be effective to protect a stack of windshields because it can only be moved with difficulty and is built of very heavy and durable structures. Such a fixture is heavy and is not justified for shipping single windshields or the like.
A possibly-ideal shipping container would have a carton that is somewhat larger than the article being protected, and has resilient damping structures that are just sufficient to protect the product against shocks applied in any direction, e.g., embedding or suspending the product at equal distance from all the container walls. However, the product may be irregularly shaped and need more protection in one direction compared to another. Also, packing material is less dense than the article and free to move (e.g., polystyrene peanuts), there is a danger that the product will settle into the packing material and not stay centered.
Polystyrene foam cushioning material can be molded in cushioning blocks that are substantially complementary with the product and fit between the product and the container walls. Shipping different objects, however, thus requires different custom sized and shaped blocks, which can be unwieldy or expensive.
Efforts have been made to provide lightweight paperboard supports as fixed spacers between edges of a protected article and internal walls of a carton. In U.S. Pat. No. 5,975,303xe2x80x94Morell, a die cut paperboard element is erectable into a deformable corner bumper pad that can be packaged, for example to engage between the outside corners of a rectilinear product and the inside corners of a protective carton.
It would be advantageous to provide an optimal container for products such as windshields, wherein the container or carton provides some protection for the product against shocks to the carton. The particular target shipping need is for cartons containing single windshields, shipped by normal commercial carriers such as United Parcel Service, Federal Express, the US Postal Service, etc. In this context, the windshields will be subject to only moderate danger or shock, perhaps typified a fall from a delivery truck. It would be advantageous to provide protection using elements that do not add undue volume or weight to the package.
Windshields are relatively heavy and are sheet-like, which factors lead to substantial load applied to an edge, if the windshield carton is placed upright on any of the edges or ends. Windshields are varied in shape, and it would be advantageous to provide a packing technique that is applicable to a wide range of sizes and shapes. Windshields are typically generally trapezoidal, i.e., wider at the bottom than the top, which presents additional challenges, if the packing technique is to employ a rectilinear outer carton.
It is an object of the invention to make the best use of the minimum amount of packing material needed to support and protect a substantially flat article such as vehicle windshield, for shipping, storage and handling in a protective carton.
It is an object to support the article (e.g., windshield) in opposed cradling structures formed in spacers that hold the edged of the article, somewhat resiliently, at a space from the carton inside walls.
Another object is optimally to form these cradling spacers to account for the packing challenges associated with windshields, including highly variable windshield dimensions for different vehicle makes and models, the particular trapezoidal and curving glass shape of many windshields, the substantial weight applied edgewise when the windshield is standing one end, etc.
The present invention provides an optimal solution for a shipping enclosure for windshields and other products with similar attributes. A packing structure supports the article in a carton, especially a generally trapezoidal laminated safety glass vehicle windshield, to be shipped in a corrugated craft carton. The article (windshield) is suspended by spacers, preferably made of integral die cut and folded blanks, that form resilient cradles along the elongated edge of the article. The carton can be rectilinear, having at each end two spaced side walls coupled by an end wall, generally forming an internal channel portion of the carton, with corners at junctions of the end wall and the side walls. A spacer is arranged to fit into this channel, so as to bear against the sidewalls and the end wall.
The spacer defines an elongated substantially V-shaped fold between two V-wall panels. The edge of the article rests in a bottom of the V-shaped fold. The spacer also has two bearing legs that can be coextensive with the V-wall panels. These legs stand in the corners of the internal channel of the carton. Spacers can be provided on two or four ends in opposed pairs. The pairs on the ends can be tapered for a trapezoidal windshield shape. A compression resistant pad can reinforce the bottom spacer. The top spacer can be placed under fillers so as to engage the article from all sides without undue clearance.
The spacer can have at least two distinct forms, for the top and bottom versus the opposed sides. Each of the preferred forms has at least one base panel, and possibly two base panels, coupled to a fold with at least one of the bearing legs, the base panel being folded to a position parallel to the end wall of the internal channel adjacent to an associated one of the corners of the internal channel.
A compression resistant material can be disposed between at least two of the end wall, the base panel and the bottom of the V-shaped fold. The lateral or carton-end spacers preferably accommodate a trapezoidal windshield shape. For this purpose, the V-wall panels increase in width along the spacer, whereby the bottom of the V-shaped fold is inclined relative to the end wall. Longitudinal shifting of any of the spacers would alter the depth of the V-shaped fold at a given point along the end wall of the carton. According to another aspect, the longitudinal position of the spacers with inclined folds is fixed, e.g., with a staple affixing a base part of the spacer to the carton or a spacing structure abutting the longitudinal end of the inclined-fold spacer. The spacing structure that fixes the inclined fold spacer can be a V-wall spacer on an adjoining end of the carton.